Acid proportioning and control system for sulphite mills



May 29, 1928. 1,671,656

C. O. SISLER ACID PROPORTIONING AND CONTROL SYSTEM FOR SULPHITE MILLS Filed Jan. 24, 1927 Patented May 29, 192 8.

UNlTEDlSTA T-ES "PATENT OFFICE;

man's min) Oil SAUL! 8T1 BRIE, OiTARIO, CANADA.

Om IBDPOB'IIOIHIG AID BYS'IEi I03 BULBBITE KILLS.

i Application fled Jenner- 24,187. Serial I0. 188,276.

This inventio; relates to an acid pro r-' tioning and control system for sulp ite mills, and the objects of the invention are to provide, a'simply constructed and'durable ll acid from the'storage tank, the resultant hot mixture, effecting considerable economy in the saving of steam, which would required if the cold acid was pumped directly into the digest'e'rs, furthermore, the operaso tion can be accomplished regardless of the Y pressure difference between the digesters. Further objects are to provide an acid proportioning and control system of the character described, so arranged that the several parts and elements involved will more satisfactorily perform the functions 7 required of them, resulting in higher efiiciency and ecomon of operation.-

A still further ob ect is to provide a means for proportioning and controlling the temrature and strength of thecooking liquor om the storage tank. With these and other objects in view the invention comprises an ejector member, the suction end of which is connected through a valve controlled pipe-with the liquor storage tank, and the discharge end, of which is connected to the suction side of the filling pump of the system.

The ejector is also connected through a valve controlled pipe line with the top and side reliefs of the digesters, whereby it is ss'ible to relieve hot liquor and gas or Eiith from one or more 0 the digesters if more than two are installed, passing it through the nozzle of the ejector to the suction side of the filling pumps into the discharge line and valve controlled filling line back into the other digester. The pass e of the relief liquor or gas which is usu y -two digesters are shown, this may be with the exception of my improvements considered as a standard construction of the average sulphlte mill, and is already known in v the art, the new and novel features of my invention and the manner of applying these features to the piping layout of the average sulphite mill is as follows and can be used 1: any sulphite mill with,two or more diges- The featuresof my invention comprise a -valve10 communicating through a pipe line 11 and pipe line 12 with the top reliefs13 and 14 controlled by valves 15 and 16; of the .digesters 17 and 18. The line 11 controlled by the valve 10 also communicates through 7 the line 12 and lines 19 and 20 with the side relief valves 21 and 22 for thedigestersl7 and 18 respectively.

From the valve 10 a pipe line 23 is run to an ejector member 24. This pipe line terminates in a nozzle 25 in the-throat of the ejector. The ejector is connected on its suction side 26 through a pipe 27 with the acid storage tank 28, while the discharge side 29 of the'ejector is connected to the suction sidev 30 of the acid filling pump 31 in turn operated in any suitable and well-known mannor by a motor 32. A check valve 33 is provided in the pipe 27 and connected to the suction side of the ejector, this check valve is so installed to permit the flow of acid from the liquor storage tank tothe ejector, but does not permit reverse flow. A control valve 34 is also provided in the pipe 27 ada ted to be operated preferably from the coo ing floor, by remote control.

The remainder of the apparatus shown in the drawing comprise the'pump discharge line which pumps the cold iquor from the storage tank 28 into the top of the di- 100 37" while the connections of the main are valve controlled in any well known manner I by 42 and cooking valve 43. The line 35 is connected to the steam main by valve controlled lines 44 and 45, while a steam line 46 is provided for cleaning the strainers.

A separator is indicated by the numeral 47, connected through a controlled line 48 with the line 12, the line 48 being also pipe connected to the relief gas cooler 50, provided with a water intake 51 and water outlet 52. For the purpose of showing the operation and advantages of my system it is assumed that digester 17 is being cooked as is usual in the process, and that it is. ready for relieving liquor or gas or combined liquor or gas as the case may be, also that the digester 18 is being filled with wood chips the usual we. would be to start the acid filling, and 11' the digester 18 with cold cooking liquor direct from the storage tank 28 However, by the use'of my system, it is now possible to relieve hot liquor or gas 'or both from digester 17 through either the side relief valve 21 or top relief valve 15 into the pipe 12 and from there to the pipe 11 throu h the valve 10, pi e line 23 to the nozzle 0 the ejector 24. he relief liquor and gas passes from the dischargeside 29 of the ejector to the suctionside of the acid fillin pump 31 and through the pump into the discharge line 35 through-the filling valve 36 in the line 37 check valve 53 into the digester 18.

The creation of the vacuum above referred to in the ejector is not absolutely essential to the satisfactor operation of my system,

as there is usual y several feet of acid in the storage tank 28, which would force the acid through the ejector to the impeller of the pump.

Accordingl if remote controlled'valve 34 is opened coo ing liquor will pass from the storage tank through said valve, through the check valve 33 to the suction side of the ejector 24 and out of the discharge end 29 of the ejector to the suction piping of the pump to the im ller of the ump.

In the impel er part of t e pump, this acid is thoroughly mixed and intermingles with the relief liquor and gas from the pipe line 23. It is then discharged into the pump discharge line 35 and through the valves and giping outlined above intothe digester 18. y regulating the opening of the remote dicating thermometer are provided on the.

pipe line' 35, for the purpose of testing the strength and temperature of the acid respectively.

As many changes could be made in the above construction, and many apparently widely different embodiments of my invention, within the scope of the claims, constructed without departing from the spirit or scope thereof, it'is intended that all matter contained in the accompanying specifications and drawings shallbe interpreted as illustrative, and not in a limiting sense.

What I claim as my invention is:

1. In a sulphite mill, an acid proportioning and control system comprising in combination, digesters, a cooking liquor storage tank, an acid filling pump, valve controlled filling and discharging conduits for the digesters, a pipe common to said conduits, a valve control in said pipe, an ejector, communicating wit the storage tank and the filling pump respectively and a pipeline connecting the e ector with the aforementioned control va ve. v

2. In a sulphite mill, an acid pro rtioning and control system, consisting o a pipe line, one end of which is in communication with the top and side relief piping of two or more digesters and contro led by means of a valve, the other end'of the said pi e line terminating in an ejector type of (itting.

pump operati'vely with a pump respectively, a pipe line connected to the digesters, valve controls for said pipeline, whereby on one or'more of the digesters being relieved, the liquor is passed to the ejector and from theejector to the ump and simultaneously the liquor is deivered from the storage tank to the pump,

from the pump through thevfilling valve,

into the fillin pipe line, and from there into the other igester.

v 5. The within described method of relieving liquor and gas from a digester which consists in concentrating the relieved liquor, delivering it under control to an ejector, mixing and p'roportioning it with the cookmg hflpor, and then pumping it into another gester.

6. In a sulphite mill, the method of pumping the hot relief liquor directly into the digesters when the 'digesters begin to fill.

7. The method of mixing in suitable pro- 5 portions cold acid from a storage tank or the like with the hot. relief liquor and gas from a digester in the, process of cooking by causing the relieved liquor and gas to mix in suitable proportions with acid liquor, and then delivering the mixture under 0 pressure back to the digester.

In witness whereof I have hereunto set my hand.

CHARLES OLAND SISLER. 

